Position sensors such as encoders, hall sensors and resolvers are used to sense a rotor position of an electric machine such as a permanent magnet (PM) machine. The output signals of a resolver contain absolute position information. The signals, which are modulated using a high-frequency excitation, are processed using specialized resolver-to-digital (R/D) converter circuits. Conventional tracking R/D converters operate under the assumption that ideal resolver signals are supplied to the R/D converter. However, in practice, various manufacturing imperfections in resolvers are always present, such as amplitude imbalance and imperfect quadrature.